Joint restraint device

ABSTRACT

A mechanical joint includes a piping element, the piping element including an element flange, the piping element defining a socket extending inwards from the element flange; a pipe length, the pipe length extending through the element flange into the socket, the pipe length defining an outer pipe surface; and a gland, the pipe length extending through the gland, the gland including a joint restraint assembly, the joint restraint assembly including a restraint base; and a gripper disposed within the restraint pocket, the gripper configured to rotate in the restraint pocket, the gripper further configured to engage the outer pipe surface to prevent removal of the pipe length from the socket.

REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No.15/490,926, filed Apr. 19, 2017, which is hereby specificallyincorporated by reference herein in its entirety.

TECHNICAL FIELD

This disclosure relates to pipe connections. More specifically, thisdisclosure relates to a joint restraint for a mechanical joint pipeconnection.

BACKGROUND

Mechanical joint pipe connections are a common method for attaching apipe length to a piping element such as a valve, a coupling, or afitting, such as a tee or elbow, or another pipe. The mechanical jointpipe connection can comprise a female socket, a gland, a gasket, and apipe length. The piping element commonly defines a female socketconfigured to receive a plain end of the pipe length and a gasket. Agland is commonly provided which slips over the plain end of the pipelength, and the gland is tightened by a series of bolts which draw thegland towards the female socket, thereby compressing the gasket.Compression of the gasket causes the gasket to engage an outer surfaceof the plain end of the pipe length, thereby forming a seal between thepipe length and the element.

Mechanical joint pipe connections are popular because mechanical jointpipe connections function with the plain end of the pipe length, unlikegroove connections or flanged connections that require preparation ofthe plain end of the pipe length. The ability to function with the plainend allows for the pipe length to be cut to size in a field installationwithout requiring the time and field equipment necessary to weld aflange to the plain end or to cut a new groove in the plain end.Mechanical joint pipe connections can be assembled quickly with commonhand tools such as a wrench or ratchet.

However, typical mechanical joint pipe connections do not provide for apositive retention mechanism other than friction of the gasket acting onthe plain end of the length. The lack of a positive retention mechanismcan compromise the seal or lead to the plain end pulling out of thefemale socket when the connection is subjected to high tension force oreffects such as water hammer. Some mechanical joint pipe connections canincorporate a joint restraint mechanism configured to mechanicallyengage the plain end of the pipe; however, existing joint restraintmechanisms can exert high stresses upon the plain end of the pipe lengthwhich can lead to deformation, creep, and cracking of the plain end ofthe pipe length during installation or operation. Deformation, creep,and cracking can lead to failure of the seal or failure of the pipelength itself which can result in leaks or environmental contamination.

SUMMARY

It is to be understood that this summary is not an extensive overview ofthe disclosure. This summary is exemplary and not restrictive, and it isintended to neither identify key or critical elements of the disclosurenor delineate the scope thereof. The sole purpose of this summary is toexplain and exemplify certain concepts of the disclosure as anintroduction to the following complete and extensive detaileddescription.

Disclosed is a gland comprising an annular ring, the annular ringdefining a gland bore, the gland bore defining a gland axis; and a jointrestraint assembly, the joint restraint assembly comprising a restraintbase, the restraint base attached to the annular ring, the restraintbase defining a restraint pocket; the restraint pocket comprising arestraint pivot disposed within the restraint pocket; a gripper, thegripper disposed within the restraint pocket, the gripper engaging therestraint pivot, the gripper configured to rotate about the restraintpivot; and a spring clip disposed within the restraint pocket, thespring clip biasing the gripper to rotate inwards towards the glandaxis.

Also disclosed is a mechanical joint comprising a piping element, thepiping element comprising an element flange, the piping element defininga socket extending inwards from the element flange; a pipe length, thepipe length extending through the element flange into the socket, thepipe length defining an outer pipe surface; and a gland, the pipe lengthextending through the gland, the gland comprising a joint restraintassembly, the joint restraint assembly comprising a restraint base, therestraint base comprising a restraint pivot; and a gripper, the gripperengaging the restraint pivot, the gripper configured to rotate about therestraint pivot, the gripper configured to engage the outer pipe surfaceto prevent removal of the pipe length from the socket.

Also disclosed is a method of coupling a pipe length to a pipingelement, the method comprising sliding a gland over a plain end of thepipe length, the gland comprising a joint restraint assembly, the pipelength defining an outer pipe surface; inserting the plain end of thepipe length into a socket defined by the piping element; fastening thegland to the piping element; and activating the joint restraint assemblyto prevent removal of the pipe length from the socket, activating thejoint restraint assembly comprising rotating a gripper in an engagementdirection about a restraint pivot of the gland; and engaging the gripperwith the outer pipe surface in an initial engagement position.

Various implementations described in the present disclosure may includeadditional systems, methods, features, and advantages, which may notnecessarily be expressly disclosed herein but will be apparent to one ofordinary skill in the art upon examination of the following detaileddescription and accompanying drawings. It is intended that all suchsystems, methods, features, and advantages be included within thepresent disclosure and protected by the accompanying claims. Thefeatures and advantages of such implementations may be realized andobtained by means of the systems, methods, features particularly pointedout in the appended claims. These and other features will become morefully apparent from the following description and appended claims, ormay be learned by the practice of such exemplary implementations as setforth hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

The features and components of the following figures are illustrated toemphasize the general principles of the present disclosure. The drawingsare not necessarily drawn to scale. Corresponding features andcomponents throughout the figures may be designated by matchingreference characters for the sake of consistency and clarity.

FIG. 1 is a perspective view of a piping element assembly in accordancewith one aspect of the disclosure.

FIG. 2 is cross sectional view of the pipe element assembly of FIG. 1taken across line 2-2 shown in FIG. 1.

FIG. 3 is a detail view of a mechanical joint of the pipe elementassembly comprising a gland taken from Detail 3 shown in FIG. 2.

FIG. 4 is a detail view of the mechanical joint of the pipe elementassembly taken from Detail 3 shown in FIG. 2 with a gripper of the glandof FIG. 3 in an initial engagement position.

FIG. 5 is a detail view of the mechanical joint of the pipe elementassembly taken from Detail 3 shown in FIG. 2 with the gripper of thegland of FIG. 3 in a final engagement position.

FIG. 6 is a detail view of the mechanical joint of the pipe elementassembly taken from Detail 3 shown in FIG. 2 with the gripper of thegland of FIG. 3 in a lifted position.

FIG. 7 is a side view of the gripper of the gland of FIG. 3.

FIG. 8 is a perspective view of the gripper of the gland of FIG. 3.

FIG. 9 is a perspective view of a spring clip of the gland of FIG. 3.

FIG. 10 is a perspective view of a gland of FIG. 3.

FIG. 11 is a perspective view of the gland in accordance with anotheraspect of the disclosure.

FIG. 12A is a cross-sectional view of the gland of FIG. 3 taken alongline 12-12 shown in FIG. 10.

FIG. 12B is a cross-sectional view of the gland in accordance withanother aspect of the disclosure.

FIG. 13 is a perspective view of the mechanical joint of FIG. 3comprising a deactivation mechanism in accordance with one aspect of thedisclosure.

FIG. 14 is a perspective view of the mechanical joint of FIG. 3comprising the gland of FIG. 12B and the deactivation mechanism inaccordance with another aspect of the disclosure.

DETAILED DESCRIPTION

The present disclosure can be understood more readily by reference tothe following detailed description, examples, drawings, and claims, andthe previous and following description. However, before the presentdevices, systems, and/or methods are disclosed and described, it is tobe understood that this disclosure is not limited to the specificdevices, systems, and/or methods disclosed unless otherwise specified,and, as such, can, of course, vary. It is also to be understood that theterminology used herein is for the purpose of describing particularaspects only and is not intended to be limiting.

The following description is provided as an enabling teaching of thepresent devices, systems, and/or methods in its best, currently knownaspect. To this end, those skilled in the relevant art will recognizeand appreciate that many changes can be made to the various aspects ofthe present devices, systems, and/or methods described herein, whilestill obtaining the beneficial results of the present disclosure. Itwill also be apparent that some of the desired benefits of the presentdisclosure can be obtained by selecting some of the features of thepresent disclosure without utilizing other features. Accordingly, thosewho work in the art will recognize that many modifications andadaptations to the present disclosure are possible and can even bedesirable in certain circumstances and are a part of the presentdisclosure. Thus, the following description is provided as illustrativeof the principles of the present disclosure and not in limitationthereof.

As used throughout, the singular forms “a,” “an” and “the” includeplural referents unless the context clearly dictates otherwise. Thus,for example, reference to “an element” can include two or more suchelements unless the context indicates otherwise.

Ranges can be expressed herein as from “about” one particular value,and/or to “about” another particular value. When such a range isexpressed, another aspect includes from the one particular value and/orto the other particular value. Similarly, when values are expressed asapproximations, by use of the antecedent “about,” it will be understoodthat the particular value forms another aspect. It will be furtherunderstood that the endpoints of each of the ranges are significant bothin relation to the other endpoint, and independently of the otherendpoint.

For purposes of the current disclosure, a material property or dimensionmeasuring about X or substantially X on a particular measurement scalemeasures within a range between X plus an industry-standard uppertolerance for the specified measurement and X minus an industry-standardlower tolerance for the specified measurement. Because tolerances canvary between different materials, processes and between differentmodels, the tolerance for a particular measurement of a particularcomponent can fall within a range of tolerances.

As used herein, the terms “optional” or “optionally” mean that thesubsequently described event or circumstance can or cannot occur, andthat the description includes instances where said event or circumstanceoccurs and instances where it does not.

The word “or” as used herein means any one member of a particular listand also includes any combination of members of that list. Further, oneshould note that conditional language, such as, among others, “can,”“could,” “might,” or “may,” unless specifically stated otherwise, orotherwise understood within the context as used, is generally intendedto convey that certain aspects include, while other aspects do notinclude, certain features, elements and/or steps. Thus, such conditionallanguage is not generally intended to imply that features, elementsand/or steps are in any way required for one or more particular aspectsor that one or more particular aspects necessarily include logic fordeciding, with or without user input or prompting, whether thesefeatures, elements and/or steps are included or are to be performed inany particular aspect.

Disclosed are components that can be used to perform the disclosedmethods and systems. These and other components are disclosed herein,and it is understood that when combinations, subsets, interactions,groups, etc. of these components are disclosed that while specificreference of each various individual and collective combinations andpermutation of these may not be explicitly disclosed, each isspecifically contemplated and described herein, for all methods andsystems. This applies to all aspects of this application including, butnot limited to, steps in disclosed methods. Thus, if there are a varietyof additional steps that can be performed it is understood that each ofthese additional steps can be performed with any specific aspect orcombination of aspects of the disclosed methods.

Disclosed is a gland and associated methods, systems, devices, andvarious apparatus. The gland comprises an annular ring and a jointrestraint assembly. It would be understood by one of skill in the artthat the disclosed gland is described in but a few exemplary embodimentsamong many. No particular terminology or description should beconsidered limiting on the disclosure or the scope of any claims issuingtherefrom.

FIG. 1 shows a perspective view of a piping element assembly 100. Thepipe element assembly 100 can comprise a piping element 110, a firstgland 124 a, a second gland 124 b, a first pipe length 102 a, and asecond pipe length 102 b. The pipe lengths 102 a,b are shown asrelatively short lengths for exemplary purposes, and each of the pipelengths 102 a,b can be significantly longer than shown. In application,the pipe lengths 102 a,b can be comprised by a piping system or a pipinginfrastructure, such as a municipal water infrastructure or any otherpiping system or piping infrastructure.

In the present aspect, the piping element 110 can be a valve 112, suchas a gate valve, a ball valve, a butterfly valve, a globe valve, or anyother suitable type of valve. In other aspects, the piping element 110can be a coupling configured to mechanically couple and seal the firstpipe length 102 a with the second pipe length 102 b in fluidcommunication. In other aspects, the piping element 110 can be a pipefitting, such as a tee, an elbow, a reducer, a wye, a shaped fitting, orany other suitable type of pipe fitting. In other aspects, the pipingelement 110 can be equipment such as a fire hydrant. In such aspects,the piping element assembly 100 may not comprise the second gland 124 band the second pipe length 102 b, and the fire hydrant can define an endof a leg of the municipal water infrastructure.

The piping element 110 can comprise a first element flange 122 a and asecond element flange 122 b. The first element flange 122 a can bedisposed opposite from the second element flange 122 b. The firstelement flange 122 a, the first gland 124 a, and the first pipe length102 a can define a first mechanical joint 120 a. The second elementflange 122 b, the second gland 124 b, and the second pipe length 102 bcan define a second mechanical joint 120 b. The first mechanical joint120 a can be configured to mechanically couple and seal the first pipelength 102 a to the piping element 110, and the second mechanical joint120 b can be configured to mechanically couple and seal the second pipelength 102 b to the piping element 110.

The first gland 124 a can be coupled to the first element flange 122 aby a first plurality of fasteners 126 a. In the present aspect, thefirst plurality of fasteners 126 a can be T-bolts; however in otheraspects, the fasteners 126 a can be bolts, studs, or any other suitabletype of fasteners. Each of the first plurality of fasteners 126 a canengage, a flange slot 128 a, a flange hole 130 a, or similar flangeslots 128 a or flange holes 130 a defined by the first element flange122 a. The first plurality of fasteners 126 a can be configured to drawthe first gland 124 a towards the first element flange 122 a.

The first gland 124 a can comprise a first annular ring 125 a and afirst plurality of joint restraint assemblies 134 a. In the presentaspect, the first gland 124 a can comprise six joint restraintassemblies 134 a; however, the quantity of joint restraint assemblies134 a should not be viewed as limiting, and the first gland 124 a cancomprise greater or fewer joint restraint assemblies 134 a in otheraspects. In the present aspect, the joint restraint assemblies 134 a canbe equally spaced about a circumference of the first annular ring 125 a;however, this distribution should not be viewed as limiting, and thejoint restraint assemblies 134 a can be distributed in any suitablearrangement.

The first gland 124 a is shown in FIG. 1 in an activated configuration.In the activated configuration, each of the joint restraint assemblies134 a of the first gland 124 a can engage the first pipe length 102 a inorder to prevent removal of the first pipe length 102 a from the pipingelement 110.

The second gland 124 b can be coupled to the second element flange 122 bby a second plurality of fasteners 126 b. In the present aspect, thesecond plurality of fasteners 126 b can be T-bolts; however, in otheraspects, the fasteners 126 b can be bolts, studs, or any other suitabletype of fasteners. Each of the second plurality of fasteners 126 b canengage a flange slot 128 b, a flange hole 130 b, or similar flange slots128 b or flange holes 130 b defined by the second element flange 122 b.The second plurality of fasteners 126 b can be configured to draw thesecond gland 124 b towards the second element flange 122 b.

The second gland 124 b can comprise a second annular ring 125 b and asecond plurality of joint restraint assemblies 134 b. In the presentaspect, the second gland 124 b can be similar in structure to the firstgland 124 a. The second gland 124 b can comprise six joint restraintassemblies 134 b; however, the quantity of joint restraint assemblies134 b should not be viewed as limiting, and the second gland 124 b cancomprise greater or fewer joint restraint assemblies 134 b in otheraspects. In the present aspect, the joint restraint assemblies 134 b canbe equally spaced about a circumference of the second annular ring 125b; however, this distribution should not be viewed as limiting, and thejoint restraint assemblies 134 b can be distributed in any suitablearrangement.

The second gland 124 b is shown in FIG. 1 in a deactivated configurationin which each of the joint restraint assemblies 134 b of the secondgland 124 b is prevented from engaging the second pipe length 102 b by adeactivation mechanism 136. In the present aspect, the deactivationmechanism 136 can be an o-ring, rubber band, bungee cord, or similarelastic member, and is discussed in further detail below.

FIG. 2 is a cross sectional view of the pipe element assembly 100 ofFIG. 1 taken across line 2-2 shown in FIG. 1. The piping element 110 candefine a first socket 222 a sized to accept the piping element 110within the first element flange 122 a. The piping element 110 can alsodefine a second socket 222 b sized to accept the piping element 110within the second element flange 122 b. The piping element can define anelement bore 210 extending through the piping element 110 from the firstsocket 222 a to the second socket 222 b. The element bore 210 can berepresentative of any piping element 110, such as a coupling or pipefitting. In aspects in which the piping element 110 is an angled fittingsuch as an elbow fitting, the element bore 210 can be curved or angled.In aspects in which the piping element 110 is a fitting such as a tee ora wye, the element bore 210 can be forked or defined by multiple boresintersecting each other. In the present aspect, the element bore 210 canbe substantially cylindrical, and the element bore 210 can define anelement bore axis 201 therethrough.

The first annular ring 125 a of the first gland 124 a can define a firstgland bore 206 a. The first gland bore 206 a can define a first glandaxis 207 a which can be substantially coincident with the element boreaxis 201 such that the first gland bore 206 a and the element bore 210can be coaxial. The first pipe length 102 a can extend through the firstgland bore 206 a into the first socket 222 a. The first pipe length 102a can be substantially coaxial with the first gland axis 207 a and theelement bore axis 201.

The second annular ring 125 b of the second gland 124 b can define asecond gland bore 206 b. The second gland bore 206 b can define a secondgland axis 207 b which can be substantially coincident with the elementbore axis 201 and the first gland axis 207 a such that the first glandbore 206 a, the second gland bore 206 b, and the element bore 210 can besubstantially coaxial. The second pipe length 102 b can extend throughthe second gland bore 206 b into the second socket 222 b. The secondpipe length 102 b can be substantially coaxial with the first gland axis207 a, the second gland axis 207 b, and the element bore axis 201.

The mechanical joint 120 a of the pipe element assembly 100 can furthercomprise a first gasket 228 a, and the mechanical joint 120 b of thepipe element assembly 100 can further comprise a second gasket 228 b.The first gasket 228 a can be disposed axially between the pipingelement 110 and the first gland 124 a within the first socket 222 a. Thefirst gasket 228 a can be configured to seal against a first outer pipesurface 204 a defined by the first pipe length 102 a. The second gasket228 b can be disposed axially between the piping element 110 and thesecond gland 124 b within the second socket 222 b. The second gasket 228b can be configured to seal against a second outer pipe surface 204 bdefined by the second pipe length 102 b.

As previously described, the first gland 124 a is shown in the activatedconfiguration wherein a first gripper 232 a of each of the jointrestraint assemblies 134 a can be positioned to engage the first outerpipe surface 204 a. In the present aspect, the first grippers 232 a arein a final engagement position which prevents any withdrawal of thefirst pipe length 102 a from the first socket 222 a. The finalengagement position is shown and further described below with respect toFIG. 5.

The second gland 124 b is shown in the deactivated configuration whereina second gripper 232 b of each of the joint restraint assemblies 134 bcan be disengaged from the second outer pipe surface 204 b by thedeactivation mechanism 136. In the present aspect, the second grippers232 b are shown in a disengaged position in which the second pipe length102 b can freely be inserted, withdrawn, or completely removed from thesecond socket 222 b. The disengaged position is shown and furtherdescribed below with respect to FIG. 3.

FIG. 3 is a detail view of the second mechanical joint 120 b of the pipeelement assembly 100 taken from Detail 3 shown in FIG. 2. The secondmechanical joint 120 b can be representative of either of the aspects ofthe mechanical joints 120 a,b as shown in FIG. 1, and components of thepipe element assembly 100 are referred to in generality hereafter. Forexample, the second mechanical joint 120 b is simply referred to as themechanical joint 120 below.

As previously described, the gland 124 in the present aspect can beplaced in the deactivated configuration, and the gripper 232 can therebybe placed in the disengaged position which allows the pipe length 102 tofreely move into the socket 222 in an insertion direction 398 oroutwards from the socket 222 in a withdrawal direction 399. The pipingelement 110 can define a pipe shoulder 323 between the socket 222 andthe element bore 210. The pipe shoulder 323 can be configured to providea positive stop for a plain end 302 of the pipe length 102 which canlimit a depth of insertion of the pipe length 102 into the socket 222.

The pipe element 110 can define a gasket groove 325. The gasket groove325 can define a taper, and the gasket groove 325 can define asubstantially triangular or trapezoidal profile. The gasket groove 325can be shaped to receive the gasket 228. The annular ring 125 of thegland 124 can be configured to engage the gasket 228. The annular ring125 can define an engagement bevel 326. The engagement bevel 326 can besubstantially frustoconical in shape, and the engagement bevel 326 canface radially inward with respect to the bore axis 201 and the glandaxis 207 (both shown in FIG. 2). Tightening of the fasteners 126 candraw the gland 124 towards the element flange 122 of the pipe element110, thereby compressing the gasket 228 in the gasket groove 325. Theengagement bevel 326 and the taper of the gasket groove 325 cancooperate to compress and deform the gasket 228 radially inward withrespect to the bore axis 201 and gland axis 207. Compression anddeformation of the gasket 228 can press an inner gasket surface 328 ofthe gasket 228 against the outer pipe surface 204, thereby energizingthe gasket 228 and creating a seal between the gasket 228 and the outerpipe surface 204. With the gasket 228 compressed, friction between theinner gasket surface 328 and the outer pipe surface 204 can resistmovement of the pipe length 102 in both the insertion direction 398 andthe withdrawal direction 399.

The socket 222 can taper radially outward as the socket 222 extendsaxially away from the gasket groove 325 and towards the pipe shoulder323. The gland bore 206 can taper radially outward as the gland bore 206extends axially away from the engagement bevel 326. The respectivetapers of the socket 222 and the gland bore 206 can provide clearance oneither side of the gasket 228 to allow the pipe length 102 to tilt anddemonstrate limited angular deflection relative to the bore axis 201 andgland axis 207 (shown in FIG. 2). In the present aspect, the pipe length102 can demonstrate angular deflection of up to 3 degrees relative tothe bore axis 201; however, this value should not be viewed as limiting.The socket 222 and the gland 124 can be sized and shaped to allow forlarger or smaller angular deflection of the pipe length 102.

In the present aspect, the angular deflection can be limited by the sizeand geometry of the socket 222, and the gland 124; however, the jointrestraint assembly 134 can tolerate larger values of angular deflection.The taper of the gland bore 206 can also aid in slipping the gland 124over the plain end 302 of the pipe length 102 during installation. Thetaper and sizing of the gland bore 206 can be configured to provideclearance for the gripper 232 to clear the outer pipe surface 204 in thedeactivated configuration.

Each joint restraint assembly 134 can comprise a restraint base 334, aspring clip 333, and a one of the grippers 232. The joint restraintassembly 134 can be assembled on the restraint base 334. In the presentaspect, the restraint base 334 can be integrally defined by the gland124; however in other aspects, the restraint base 334 can be a separatecomponent which can be attached or fastened to the annular ring 125 ofthe gland 124. In some aspects, a position of the restraint base 334 onthe annular ring 125 can be adjusted, such as by moving the restraintbase 334 radially inward or outward relative to the gland axis 207(shown in FIG. 2). Such adjustment can allow the gland 124 to beconfigured for different sizes of pipe lengths 102 having differentouter diameters. In some aspects, the restraint bases 334 can also beadjusted on the annular ring 125 axially relative to the gland axis 207.The restraint base 334 can define a restraint pocket 340 and a restraintpivot 342. The gripper 232 and the spring clip 333 can be disposedwithin the restraint pocket 340.

The gripper 232 can rotate about the restraint pivot 342 such that theengagement end 332 of the gripper 232 can be drawn into and out ofcontact with the outer pipe surface 204. The gripper 232 can define agripper bearing surface 346, and the restraint pivot 342 can define arestraint bearing surface 344. The gripper bearing surface 346 can beshaped complimentary to the restraint bearing surface 344, and thegripper bearing surface 346 can be in facing contact with the restraintbearing surface 344. The gripper bearing surface 346 can be configuredto slide around the restraint bearing surface 344 as the gripper 232rotates about the restraint pivot 342.

The gripper 232 can define an engagement end 332 and a lever end 330.The engagement end 332 can be disposed opposite from the lever end 330with the gripper bearing surface 346 defined between the engagement end332 and the lever end 330. The engagement end 332 can extend into thegland bore 206 towards the gland axis 207 (shown in FIG. 2). The springclip 333 can bias the gripper 232 to rotate about the restraint pivot342 towards engagement with outer pipe surface 204. Specifically, anengagement leg 322 of the spring clip 333 can press on the engagementend 332 of the gripper 232. A retention tab 324 of the spring clip 333can engage a locator bore 320 defined by the restraint base 334. Theengagement of the retention tab 324 with the locator bore 320 canposition and secure the spring clip 333 within the restraint pocket 340,and the spring clip 333 can thereby maintain the engagement between thegripper 232 and the restraint pivot 342.

In the deactivated configuration, the deactivation mechanism 136 canprevent rotation of the gripper 232 towards engagement with the outerpipe surface 204. In the present aspect, the deactivation mechanism 136can be elastic, and tension of the deactivation mechanism 136 canoverpower the spring clips 333. The deactivation mechanism 136 can pullon the lever end 330 of the gripper 232 to position the gripper 232 inthe disengaged position wherein the gripper 232 is out of contact withthe outer pipe surface 204. The deactivation mechanism 136 can comprisea stretchable material such as an O-ring, a rubber band, a bungee cord,or any other suitable elastically stretchable material.

In the present aspect, the deactivation mechanism 136 can simultaneouslydeactivate all of the joint restraint assemblies 134 of the gland 124.Removing the deactivation mechanism 136 from the gripper 232 canactivate each joint restraint assembly 134, as shown in FIG. 4. Thedeactivation mechanism 136 can be individually slipped off of the leverend 330 of each gripper 232 to individually activate the respectivejoint restraint assembly 134, or the deactivation mechanism 136 can becut, such as with scissors, which can simultaneously activate all of thejoint restraint assemblies 134 of the gland 124. In some aspects, thelever end 330 can define a deactivation feature (not shown) such as anextension, a hook, or a pin configured to engage the deactivationmechanism 136. The deactivation feature can be configured to preventpinching of the deactivation mechanism 136 between the lever end 330 andthe restraint base 334 which can bind the gripper 232 under someconditions.

FIG. 4 is a detail view of the mechanical joint 120 of the pipe elementassembly 100 taken from Detail 3 shown in FIG. 2 with the gripper 232shown in an initial engagement position. The gripper 232 can rotateabout the restraint pivot 342 under the bias of the spring clip 333. Therestraint bearing surface 344 can define a pivot radius of curvature R₁and a pivot center axis P₁. The pivot center axis P₁ can beperpendicular to both an axial direction and a radial direction withrespect to the gland axis 207 (shown in FIG. 12). The complimentaryshapes of the gripper bearing surface 346 and the restraint bearingsurface 344 allows the gripper 232 to rotate around the pivot centeraxis P₁ while maintaining facing contact between the gripper bearingsurface 346 and the restraint bearing surface 344.

The spring clip 333 biases the gripper 232 to rotate about the pivotcenter axis P₁ in an engagement direction 499 (counter-clockwise in theaspect shown). The deactivation mechanism 136 (shown in FIG. 3) biasesthe gripper 232 to rotate in a disengagement direction 498 (clockwise inthe aspect shown). Once the deactivation mechanism 136 (shown in FIG. 3)has been removed and the joint restraint assembly 134 is placed in theactivated configuration, the gripper 232 can rotate in the engagementdirection 499 such that the engagement end 332 engages the outer pipesurface 204.

The gripper 232 can define a leading edge 428 and a trailing edge 426 atopposite sides of the engagement end 332. The leading edge 428 and thetrailing edge 426 are named with respect to rotation in the engagementdirection 499. The gripper 232 can comprise a plurality of grippingprotuberances 430 disposed on the engagement end 332. Each grippingprotuberance 430 can extend outwards from the engagement end 332, andthe gripping protuberances 430 can be configured to engage or dig intothe outer pipe surface 204 of the pipe length 102. In the presentaspect, a row of gripping protuberances 430 disposed closest to theleading edge 428 can define a leading row 432 of gripping protuberances430.

The initial engagement position can describe a position of the gripper232 when the leading row 432 first contacts the outer pipe surface 204when rotating the gripper 232 in the engagement direction 499. In theinitial engagement position, the leading row 432 can rest in lightcontact with the outer pipe surface 204 under the bias of the springclip 333, and the leading row 432 of gripping protuberances 430 has notyet significantly dug into the outer pipe surface 204. As shown, thosegripping protuberances 430 not in the leading row 432 are disengagedfrom the outer pipe surface 204 in the initial engagement position.

In the initial engagement position, the gripper 232 does notsubstantially resist movement of the pipe length 102 in the insertiondirection 398 into the socket 222. The gripping protuberances 430 arebiased to permit movement of the pipe length 102 in the insertiondirection 398 without digging into the outer pipe surface 204. Thegripper 232 can rotate imperceptibly in the disengagement direction 498to allow the leading row 432 of gripping protuberances 430 to slideacross the outer pipe surface 204.

However, moving the pipe length 102 in the withdrawal direction 399outwards from the socket 222 can cause the leading row 432 of grippingprotuberances 430 to “bite” and dig into the outer pipe surface 204.Once the leading row 432 of gripping protuberances 430 dig into theouter pipe surface 204, movement of the pipe length 102 in thewithdrawal direction 399 causes rotation of the gripper 232 in theengagement direction 499. The engagement end 332 of the gripper 232 canbe configured to exert increasing pressure on the outer pipe surface 204when the gripper 232 is rotated about the restraint pivot 342 in theengagement direction 499. Rotational movement of the gripper 232 aboutthe restraint pivot in the engagement direction 499 results in aradially inward component of movement of the engagement end 332 towardsthe gland axis 207 (shown in FIG. 2). As the engagement end 332 rotatesin the engagement direction 499 and moves radially inward, an increasingnumber of the gripping protuberances 430 engage the outer pipe surface204.

The radially inward component of movement of the engagement end 332results in an inward pinching action of the pipe length 102 betweenopposing pairs of joint restraint assemblies 134. The inward pinchingaction causes the gripping protuberances 430 to exert increasingpressure on the outer pipe surface 204. The pipe length 102 resists theinward pinching action which prevents further rotation of the grippers232 in the engagement direction which thereby resists further movementof the pipe length 102 in the withdrawal direction 399. Movement of thepipe length 102 in the insertion direction 398 can relax the inwardpinching action by rotating the grippers 232 slightly in thedisengagement direction 498.

Accordingly, each joint restraint assembly 134 reacts and self-adjuststo a withdrawal force acting on the pipe length 102 in the withdrawaldirection 399 by exerting only as much force and pressure as required toprevent further movement of the pipe length 102 in the withdrawaldirection 399. The self-adjustment and variable engagement of thegrippers 232 also allows each joint restraint assembly 134 to adjust tovariations of the outer diameter of the pipe length 102. Variation inthe outer diameter of the pipe length 102 can be caused, for example andwithout limitation, by manufacturing tolerance, a wall thickness of thepipe length 102, different dimensional specifications for pipe lengths102 manufactured to different industry standards, ovality of the pipelength 102, or deformation of the pipe length 102. The joint restraintassemblies 134 are insensitive to such variations because each jointrestraint assembly 134 can self-adjust independent of the other jointrestraint assemblies 134. In other aspects, the joint restraint assembly134 can also be adjusted radially inward and outward to accommodate pipelengths 102 of significantly different outer diameters. In otheraspects, the grippers 232 can be provided with engagement ends 332 ofdifferent lengths, and the grippers 232 can be interchanged toaccommodate pipe lengths 102 of significantly different outer diameters.For example, the grippers 232 of an aspect of the gland 124 configuredfor use with a 6″ pipe can be replaced with grippers 232 with anelongated engagement end 332 to convert the gland 124 for use with a 4″pipe.

If the withdrawal of the pipe length 102 continues, the gripper 232 cancontinue to rotate in the engagement direction 499 until the lever end330 of the gripper 232 contacts a stop surface 540 defined by therestraint base 334, as shown in FIG. 5. FIG. 5 is a detail view of themechanical joint 120 of the pipe element assembly 100 taken from Detail3 shown in FIG. 2 with the gripper 232 shown in the final engagementposition. Contact between the gripper 232 and the stop surface 540 canprevent further rotation of the gripper 232 about the restraint pivot342. When the lever end 330 contacts the stop surface 540, the gripper232 can be in the final engagement position.

In the final engagement position, all of the gripping protuberances 430can be engaged with the outer pipe surface 204, thereby maximizingtraction of the gripper 232 on the pipe length 102. The stop surface 540prevents the gripper 232 from further rotating in the engagementdirection 499, thereby preventing further movement of the pipe length102 in the withdrawal direction 399 without bending the grippingprotuberances 430 or shearing the gripping protuberances 430 or materialfrom the outer pipe surface 204. The pipe length 102 can still readilymove in the insertion direction 398, resulting in rotation of thegripper 232 in the disengagement direction 498 and ultimately reducingthe inward pinching action acting on the pipe length 102.

Engagement by the gripper 232 of each joint restraint assembly 134 canoccur over a full range of motion between the initial engagementposition and the final engagement position. The grippers 232independently engage the pipe length 102, and the degree of engagementcan be based on numerous variables. The gripper 232 of each jointrestraint assembly 134 can be in a different position and a differentdegree of engagement. For instance, a first gripper 232 of themechanical joint 120 can be in the initial engagement position, a secondgripper 232 of the mechanical joint 120 can be positioned between theinitial engagement position and the final engagement position, and athird gripper 232 of the mechanical joint 120 can be in the finalengagement position. Relevant variables include, but are not limited to,the outer diameter of the pipe length 102, ovality of the pipe length102, angular deflection of the pipe length 102 relative to the glandaxis 207 (shown in FIG. 2), and a magnitude of force exerted on the pipelength 102 to insert or withdrawal the pipe length 102 from the socket222. As conditions change, each gripper 232 can independently react toincrease or decrease engagement with the pipe length 102. For example,if the pipe element assembly 100 is buried and settles over time or issubjected to a disruptive event such as an earthquake, each individualjoint restraint assembly 134 can adjust independently to the newconditions of tension and angular alignment of the pipe length 102.

FIG. 6 is a detail view of the mechanical joint 120 of the pipe elementassembly 100 taken from Detail 3 shown in FIG. 2 with the gripper 232shown in a lifted position. The lifted position is not a normaloperating position, but can exemplify the ability of the joint restraintassembly 134 to compensate and adjust for misalignment duringinstallation of the gland 124 over the pipe length 102.

In the lifted position, the gripper 232 can lift off of the restraintpivot 342 such that the gripper bearing surface 346 at least partiallybreaks contact with the restraint bearing surface 344. In the liftedposition, the engagement end 332 can move radially outwards with respectto the gland axis 207 (shown in FIG. 2) further than normally allowablein the disengaged position of FIG. 3. The ability for the gripper 232 tolift off of the restraint pivot 342 can provide additional clearance forinserting the pipe length 102 through the gland 124. In other aspects,the restraint pocket 340 can be sized and shaped to prevent lifting ofthe gripper 232 relative to the restraint pivot 342. In other aspects,the restraint pivot 342 can be configured to prevent lifting of thegripper 232. For example, in some aspects, the restraint pivot 342 canbe a bolt, a rod, or a similar fastener extending through a bore definedby the gripper 232.

FIG. 7 is a side view of the gripper 232 of FIG. 2. The gripper 232 candefine a first gripper surface 702 and a second gripper surface 704disposed opposite from the first gripper surface 702. The gripperbearing surface 346 can be defined by a portion of the first grippersurface 702. The second gripper surface 704 can define the trailing edge426, and the first gripper surface 702 can define the leading edge 428.The gripper 232 can also define a top gripper surface 706 disposed onthe lever end 330 opposite from the plurality of gripping protuberances430. The gripper bearing surface 346 can be shaped complimentary to therestraint bearing surface 344 (shown in FIG. 3). The gripper bearingsurface 346 can define a gripper radius of curvature R₂ which can besubstantially equal to the pivot radius of curvature R₁ (shown in FIG.4).

A contour of the edges of the plurality of gripping protuberances 430can define an engagement radius of curvature R₃ of the grippingprotuberances 430. The engagement radius of curvature R₃ can smoothlyroll the gripping protuberances 430 into increasing engagement with theouter pipe surface 204 (shown in FIG. 3) as the pipe length 102 is movedin the withdrawal direction 399 (shown in FIG. 3) and the gripper 232 isrotated in the engagement direction 499 (shown in FIG. 4). The rollingof the gripping protuberances 430 can smoothly increase pressure appliedto the pipe length 102 by each gripper 232. A horizontal offset betweena center point of the radius of curvature R₃ and a center point of thegripper radius of curvature R₂, among other variables, can also affect amagnitude to the inward pinching action of the engagement end 332 of thegripper 232. By increasing the horizontal offset, a radially inwardcomponent of the motion of the engagement end 332 can be increased whenrotating the gripper 232 in the engagement direction 499. By decreasingor eliminating the horizontal offset, the radially inward component ofthe motion of the engagement end 332 can be minimized when rotating thegripper 232 in the engagement direction 499.

The contour of the edges of the gripping protuberances 430 caneffectively act as a cam profile controlling the pressure and stressexerted on the pipe length 102 upon withdrawal. In the present aspect,the engagement radius of curvature R₃ can define a constant value. Inother aspects, the contour of the edges of the gripping protuberances430 can define a different shape without a constant engagement radius ofcurvature R₃. In other aspects, the edges of the gripping protuberances430 can all be coplanar. In such an aspect, the stress and pressureexerted by the engagement end 332 can reach a maximum between theinitial engagement position and the final engagement position, and thestress and pressure can then reduce as the engagement end 332 rolls overcenter into the final engagement position. In such an aspect, thegripper 232 can be biased to remain in the final engagement position,and the pipe length 102 can be subjected to reduced residual stresses inthe final engagement position.

In the present aspect, a center row 730 of gripping protuberances 430can define a leading surface 728 and a trailing surface 726. Each of theleading surface 728 and the trailing surface 726 can be substantiallyplanar. In the final engagement position, the trailing surface can besubstantially perpendicular to the gland axis 207 (shown in FIG. 2). Anengagement angle A₁ can be defined between the leading surface 728 andthe trailing surface 726, and the center row 730 can define an angledprofile. The angled profile of the center row 730 can be configured toslide over the outer pipe surface 204 when the pipe length 102 is movedin the insertion direction 398 (as shown in FIG. 3) and to bite into theouter pipe surface 204 when the pipe length 102 is moved in thewithdrawal direction 399 (as shown in FIG. 3). In the present aspect,the engagement angle A₁ can have a value substantially equal to 30degrees; however, this value should not be viewed as limiting. In otheraspects, the value of the engagement angle A₁ can range from 15 degreesto 60 degrees. In some aspects, some or all of the grippingprotuberances 430 can each define the engagement angle A₁.

In the present aspect, the leading row 432 of gripping protuberances 430can define a leading surface 736 and a trailing surface 734. The leadingsurface 736 can be substantially planar and the trailing surface 734 canbe a curved surface swept slightly backwards towards the trailing edge426, thereby defining a curved profile. The curved surface of thetrailing surface 734 can aid the leading row 432 in biting into theouter pipe surface 204 when the pipe length 102 is moved in thewithdrawal direction 399 (as shown in FIG. 3).

In various other aspects, the angled profile of the center row 730 andthe curved profile of the leading row 432 can be exemplary of any of thegripping protuberances 430. In some aspects, all or some of the grippingprotuberances 430 can define the angled profile. In other aspects, allor some of the gripping protuberances 430 can define the curved profile.In the present aspect, the gripping protuberances 430 can define a mixof curved profiles and angled profiles.

FIG. 8 is a perspective view of the gripper 232 of FIG. 2. As shown, theplurality of gripping protuberances 430 can comprise teeth 826 and ribs828. In the present aspect, the ribs 828 can be disposed proximate thetrailing edge 426, and the teeth 826 can be disposed proximate theleading edge 428 (shown in FIG. 7). For example, the leading row 432 canbe teeth 826 in the present aspect.

The ribs 828 can each define a rib knife edge 832 extending across awidth of the respective rib 828. In the present aspect, the gripper 232can define a width of 1.5″, and the rib knife edges 832 can each definea length of 1.5″ long; however, the width of the gripper 232 and thelength of the rib knife edge 832 should not be viewed as limiting. Thegrippers 232 can range from 0.15″ to 5″ in width in various aspect, butcan have widths outside this range in other aspects. The width can bedependent upon, for example and without limitation, an outside diameterof the pipe length 102 as well as a number of grippers 232 engaging thepipe length 102 and an operating pressure of the pipe length 102. In thepresent aspect, each rib knife edge 832 can be substantially linear;however in other aspects, each rib knife edge 832 can be curved orscalloped. For example, each rib knife edge 832 can be curved tocompliment a radius of curvature of the outside diameter of the pipelength 102 in order to increase engagement area between each gripper 232and the pipe length 102. In some aspects, each rib knife edge 832 can beserrated.

Each tooth 826 can define a tooth knife edge 830 extending across awidth of the respective tooth 826. In other aspects, each tooth 826 candefine a tooth point (not shown) instead of a tooth knife edge 830. Inthe present aspect, each tooth knife edge 830 can be linear; however, inother aspects, each tooth knife edge 830 can be curved or serrated. Theteeth 826 can be separated by notches 834 disposed between adjacentteeth 826. The tooth knife edges 830, the tooth points (not shown), andthe rib knife edges 832 can each be configured to dig into the outerpipe surface 204 (shown in FIG. 3). The teeth 826 can be separated bynotches 834 disposed between adjacent teeth 826. The teeth 826 andnotches 834 can be configured to reduce available contact area of thecollective tooth knife edges 830 compared to the rib knife edges 832which can increase contact pressure at the tooth knife edges 830 of theteeth 826. Increasing contact pressure at the tooth knife edges 830 ofthe teeth 826 can aid the teeth 826 in digging or cutting into the outerpipe surface 204.

In the present aspect, the teeth 826 can be arranged in two teeth rows820; however, in other aspects, the teeth 826 may not be arranged inrows and instead can be positioned in other arrangements such as astaggered arrangement or any other suitable arrangement. Other aspectscan comprise greater or fewer teeth rows 820. In the present aspect, theribs 828 and the teeth rows 820 can be substantially parallel to thetrailing edge 426; however in other aspects, the ribs 828 and the teethrows 820 can be diagonally-oriented relative to the trailing edge 426.In some aspects, all of the gripping protuberances 430 can be teeth 826,and in other aspects, all of the gripping protuberances 430 can be ribs828. The ribs 828 and teeth 826 can be disposed in any arrangement.

The second gripper surface 704 can define a gripper pocket 840 extendinginto the gripper 232. The gripper pocket 840 can be a blind hole whichdoes not extend completely through the gripper 232. In the presentaspect, the gripper 232 can be biased towards engagement with the pipelength 102 by the spring clip 333 (shown in FIG. 3); however, in otheraspects, a coil spring (not shown) can be positioned within the gripperpocket 840, and the coil spring can bias the gripper 232 towardsengagement with the pipe length 102. Alternatively, in some aspects, thegripper pocket 840 can receive the retention tab 324 (shown in FIG. 3)to locate and retain the spring clip 333.

A deactivation catch 836 can also be defined at the lever end 330 of thegripper 232. In the present aspect, the deactivation catch 836 can be anotch extending through the lever end 330 from the second grippersurface 704 to the first gripper surface 702 (shown in FIG. 7) andinward from the top gripper surface 706 (shown in FIG. 7). In otheraspects, the deactivation catch 836 can be a through hole which extendsthrough the lever end 330 from the second gripper surface 704 to thefirst gripper surface 702 but can be enclosed by the top gripper surface706 to form an aperture rather than a notch. In other aspects, thedeactivation catch 836 can be a blind hole which does not extendcompletely through the gripper 232 to the first gripper surface 702. Thedeactivation catch 836 can also define a countersunk shoulder 838disposed around the notch, the through hole, or the blind hole. Thedeactivation catch 836 can be configured to engage some aspects of thedeactivation mechanism 136, as shown and further described below withrespect to FIGS. 13 and 14.

FIG. 9 is a perspective view of the spring clip 333 of FIG. 2. Theretention tab 324 can be disposed on a retention leg 924. The retentionleg 924 can be disposed opposite from the engagement leg 322. In someaspects, the retention tab 324 can define a slit (not shown) which canallow the retention tab 324 to spread apart in order to frictionallyengage the locator bore 320 (shown in FIG. 3). In other aspects, theretention tab 324 can comprise petals (not shown) defined byintersecting slits configured to frictionally engage the locator bore320. The spring clip 333 can demonstrate positional memory, and theengagement leg 322 can be configured to repeatedly elastically deformrelative to the retention leg 924 without plastically deforming ortaking a permanent set. The spring clip 333 can comprise a material suchas spring steel or any other suitable material. In the present aspect,the spring clip 333 can be a flat spring or V-spring; however in otheraspects, the spring clip 333 can be a wire spring or any other suitabletype of spring.

FIG. 10 is a perspective view of the gland 124 of FIG. 2. In the presentaspect, the gland 124 can define six restraint bases 334. The number ofrestraint bases 334 should not be viewed as limiting, however. Eachgland 124 can define greater or fewer than six restraint bases 334. Thenumber of restraint bases 334 can also vary with a size of the gland124. For instance, an aspect configured for use with a 24″ diameter pipecan define more restraint bases 334 than an aspect configured for usewith a 3″ diameter pipe. In the present aspect, the restraint bases 334can also be evenly distributed around the annular ring 125 of the gland124, and the restraint bases 334 can be distributed as opposing pairs1002 a,b,c of restraint bases 334. In other aspects, such as when thegland 124 defines an odd number of restraint bases 334, the restraintbases 334 may not be distributed as opposing pairs.

In the present aspect, each restraint base 334 can define a pair ofsidewalls 1034 and the respective restraint pivot 342. In the presentaspect, the sidewalls 1034 and the restraint pivot 342 can be integrallyformed with the gland 124. In other aspects, the restraint base 334 canbe a separate component which can be fastened or attached to the gland124. In the aspect of FIG. 11, the sidewalls 1034 of the restraint base334 can be integrally formed with the gland 124, and the restraint pivot342 can be a separate component fastened to the sidewalls 1034. In otheraspects, each restraint base 334 can define multiple restraint pivots342, and multiple grippers 232 (shown in FIG. 3) can be disposed withineach restraint pocket 340. In some other aspects, multiple grippers 232can be engaged with a single restraint pivot 342.

The sidewalls 1034 of each restraint base 334 can define a pair ofsidewall surfaces 1040. In the present aspect, the sidewall surfaces1040 of each restraint base 334 can be substantially parallel and can bein a facing relationship. The stop surface 540 can be substantiallyperpendicular to the sidewall surfaces 1040, and the stop surface 540can extend between the sidewall surface 1040. The sidewall surfaces 1040and the stop surface 540 of each restraint base 334 can define therespective restraint pocket 340.

The stop surface 540 of each restraint base 334 can define a springgroove 1030 recessed into the respective stop surface 540, and thelocator bores 320 can be disposed within the respective spring grooves1030. The spring grooves 1030 and the locator bores 320 can cooperate toposition and retain the spring clips 333 (shown in FIG. 3) within eachrestraint pocket 340, respectively. The gland 124 can also define aplurality of fastener holes 1010, each configured to receive a one ofthe fasteners 126.

FIG. 11 is a perspective view of another aspect of the gland 124. In thepresent aspect, the restraint pivots 342 can be a separate componentwhich can each be attached to the respective restraint base 334 by apair of fasteners 1142. In the present aspect, the fasteners 1142 can besocket-head screws which can extend through a pair of countersunk bores1144 defined by each restraint pivot 342 and into the respectivesidewalls 1034. Each sidewall 1034 can define a pivot notch 1146 sizedand shaped complimentary to the restraint pivots 342. Each restraintpivot 342 can be received and secured within a pair of pivot notches1146 of each respective restraint bases 334. Removable restraint pivots342 can be desirable in some aspects in order to provide for easiermanufacturing methods. The removable restraint pivots 342 can also bemade of a different material from the gland 124. For example, the gland124 can comprise cast iron, and the removable restrain pivots 342 cancomprise a material such as bronze which demonstrates desirable bearingproperties such as high hardness values and low friction coefficients.Removable restraint pivots 342 can also be used with aspects of thegrippers 232 which define gripper bearing bores (not shown) rather thangripper bearing surfaces 346. In such aspects, the removable restraintpivots 342 can be passed through the gripper bearing bores in order tomount the grippers 232.

FIG. 12A is a cross-sectional view of the gland 124 of FIG. 2 takenalong line 12-12 shown in FIG. 10. FIG. 12B is a cross-sectional view ofanother aspect of the gland 124. As shown in FIG. 12B, the restraintbases 334 can each comprise a pocket hood 1242, and the restraint bases334 can each define a hooded restraint pocket 1240. Each pocket hood1242 can be disposed radially external to the respective hoodedrestraint pocket 1240, and each pocket hood 1242 can cover a radiallyouter portion of the respective hooded restraint pocket 1240. The pockethoods 1242 can be configured to protect the hooded restraint pockets1240 against entry of debris, such as when the piping element assembly100 (shown in FIG. 1) is buried underground. Debris in the restraintpockets 340 or hooded restraint pockets 1240 can jam the grippers 232(shown in FIG. 3) and spring clips 333 (shown in FIG. 3) and prevent thegrippers 232 from rotating about the respective restraint pivots 342. Aspreviously described, the pivot center axis P₁ of each restraint pivot342 can be perpendicular to both the axial direction and the radialdirection with respect to the gland axis 207.

FIG. 13 is a perspective view of the mechanical joint 120 of FIG. 1comprising another aspect of the deactivation mechanism 136. Thedeactivation mechanism 136 of the present aspect can comprise an elasticmember 1338, such as an O-ring, a rubber band, a bungee cord, or anyother suitable stretchable material. The deactivation mechanism 136 canfurther comprise a plurality of deactivation blocks 1340 which can eachbe attached to the elastic member 1338 by a hooked portion 1342 of eachrespective deactivation block 1340. Each deactivation block 1340 canfurther define a blocking portion 1344 and a neck portion 1346, and theneck portion 1346 can be defined between the blocking portion 1344 andthe hooked portion 1342, thereby connecting the blocking portion 1344 tothe hooked portion 1342.

The neck portion 1346 can be sized and shaped to engage the deactivationcatch 836 defined by each gripper 232. Under tension from the elasticmember 1338, engagement between the deactivation catches 836 and neckportions 1346 at each gripper 232 can bias the grippers 232 towards thedeactivated position shown and described with respect to FIG. 3. Theblocking portion 1344 can also fit between the lever end 330 of eachgripper 232 and the respective spring clip 333. The blocking portion1344 can provide a positive stop to prevent the grippers 232 fromrotating towards the engagement position. The blocking portions 1344 canalso cover and protect the restraint pockets 340 (shown in FIG. 3) toprevent debris from entering the restraint pockets 340. In some aspects,the blocking portions 1344 can define a wedge-shape configured to beinserted into the respective restraint pocket 340.

To activate the mechanical joint 120, each of the deactivation blocks1340 can be disengaged from the respective gripper 232. The deactivationmechanism 136 can be left around the pipe length 102 as a method tostore the deactivation mechanism 136 should the mechanical joint 120need to be disassembled in the future. Alternatively, the elastic member1338 can be cut, and the deactivation mechanism 136 can be removed fromthe mechanical joint 120 and pipe length 102. Attaching eachdeactivation block 1340 to the elastic member 1338 can ensure that nodeactivation blocks 1340 are accidentally left on the mechanical joint120 after removal. In the present aspect, the deactivation blocks 1340can also be configured to automatically eject from the respectiverestraint pockets 340 (shown in FIG. 3) when tension from the elasticmember 1338 is relieved.

FIG. 14 is a perspective view of the mechanical joint 120 of FIG. 1comprising the gland 124 of FIG. 12B and another aspect of thedeactivation mechanism 136. In the present aspect, the deactivationmechanism 136 comprises a clamp 1436, such as a pipe clamp or hoseclamp. The clamp 1436 can comprise a band 1437 and a tensioner 1438. Theband 1437 can be a metal band, a plastic band, a composite strap, or anyother suitable strap or banding material. The tensioner 1438 can beconfigured to tighten the band 1437 or relax the band 1437, such as forinstallation and removal of the deactivation mechanism 136,respectively. The tensioner 1438 can be a jack bolt, a worm gear, aturnbuckle, or any other suitable tensioning mechanism. In otheraspects, the clamp 1436 may not comprise a tensioner 1438, and insteadcan comprise a buckle. In such aspects, the band 1437 can be tensionedby a separate tensioning device and secured by the buckle.

The deactivation mechanism 136 can comprise deactivation blocks 1440which can be attached to the band 1437 by a hooked portion 1442 of eachdeactivation block 1440. The deactivation block 1440 can further definea neck portion 1446 and a blocking portion 1444. The neck portion 1446can be defined between the hooked portion 1442 and the blocking portion1444. The clamp 1436 can secure the hooked portion 1442 and the neckportion 1446 in facing contact with the pocket hood 1242 of eachrespective restraint base 334. The blocking portion 1444 can furthercover the hooded restraint pocket 1240 (shown in FIG. 12B) of eachrestraint base 334. Each blocking portion 1444 can prevent debris fromentering the respective hooded restraint pocket 1240 and also block therespective gripper 232 from rotating into engagement with the pipelength 102.

Each deactivation block 1440 can further define a blocking arm 1448 anda blocking post 1450 extending from the respective blocking portion1444. The blocking arm 1448 can be wider than the blocking post 1450,and the blocking arm 1448 can be configured to engage the countersunkshoulder 838 (shown in FIG. 8) and the blocking post 1450 can beconfigured to extend into the deactivation catch 836 (shown in FIG. 8)of the respective gripper 232. The blocking portion 1444, the blockingarm 1448, and the blocking post 1450 can cooperate to prevent engagementbetween the respective gripper 232 and the pipe length 102 by blockingthe rotating motion of the respective gripper 232.

In other aspects, individual deactivation blocks (not shown) cancomprise the blocking portion 1444, the blocking arm 1448, and theblocking post 1450 without being attached to the neck portion 1446. Theindividual deactivation blocks can individually engage a one of thegrippers 232 without the use of an elastic member or clamp and can beretained by the force of the spring clip 333 (shown in FIG. 3). In otheraspects such as with the gland 124 of FIG. 10, the individualdeactivation blocks can engage the restraint pocket 340 to remain inposition.

In practice, to couple the pipe length 102 to the piping element 110,the gland 124 in the deactivated configuration can first be slid overthe plain end 302 of the pipe length 102 with the engagement bevel 326facing the plain end 302. The gasket 228 can then be slid over the plainend 302 of the pipe length 102, and the plain end 302 can be insertedinto the socket 222 until the plain end 302 contacts the pipe shoulder323. The gasket 228 can be positioned in the gasket groove 325. Thefasteners 126 can be inserted through the notches 128 or bores 130 ofthe element flange 122 and through the corresponding fastener holes 1010of the gland 124.

The fasteners 126 can be tightened, thereby drawing the gland 124towards the element flange 122 and compressing the gasket 228 within thegasket groove 325. Compressing the gasket 228 can press an inner gasketsurface 328 of the gasket 228 against the outer pipe surface 204 of thepipe length 102, thereby forming a seal between the gasket 228 and thepipe length 102. Once the gland 124 has been fastened to the elementflange 122, and the seal between the gasket 228 and the pipe length 102has been formed, the deactivation mechanism 136 can be removed from thegland 124, thereby activating the joint restraint assemblies 134. Uponactivation of the joint restraint assemblies 134, the gripper 232 ofeach joint restraint assembly 134 can rotate about the respectiverestraint pivot 342 to engage the pipe length 102. Once engaged with thepipe length 102, the joint restraint assemblies 134 can allow limitedmovement of the pipe length 102 in the withdrawal direction 399;however, the joint restraint assemblies 134 prevent removal of the pipelength 102 from the socket 222. In this context, the term “removal”indicates complete withdrawal of the pipe length 102 from the socket222.

Upon activation of the joint restraint assemblies 134, each gripper 232self-adjusts and engages the pipe length 102 based on variables such asthe outside diameter of the pipe length 102, the ovality of the pipelength 102, and the angular deflection of the pipe length 102 from thegland axis 207. For example, if the pipe length 102 demonstrates a highdegree of ovality, upon activation some of the grippers 232 can rotateto the initial engagement position while other grippers can rotate to aposition between the initial engagement position and the finalengagement position. In situations in which the outer diameter of thepipe length 102 is significantly undersized, the grippers 232 can rotateto the final engagement position upon initial activation. As the pipelength 102 moves in either the insertion direction 398 or the withdrawaldirection 399 or angularly deflects relative to the gland axis 207, thejoint restraint assemblies 134 individually adjust to increaseengagement and stress on the pipe length 102 as needed or to decreaseengagement and relieve stress on the pipe length 102 if not required torestraint the pipe length 102. The self-adjusting nature of the jointrestraint assemblies 134 can be desirable over other joint restraintmethods which induce high levels of residual stress in pipe lengths 102which can lead to cracking, creep and deformation, or failure over timeof the connection.

In some applications, the engagement ends 332 of the grippers 232 can betreated with a substance or a chemical which can bond the grippingprotuberances 430 to the outer pipe surface 204. For example, anadhesive such as a cement, an epoxy, a glue, a mastic, or any othersuitable adhesive can be applied to the grippers 232 to bond thegripping protuberances 430 to the pipe lengths 102. Another example, achemical agent configured to react and soften the material of the pipelengths 102 can be applied to the gripping protuberances 430, and thegrippers 232 can chemically weld to the outer pipe surface 204 uponre-hardening of the material of the pipe length 102.

The joint restraint assemblies 134 can also be desirable over connectionmethods which require special end configurations for the pipe lengths102 rather than plain ends 302. For example, some connection methodsrequire that the pipe length 102 define a feature such as a flange,groove, or threading at the end of the pipe length 102. Unfortunately,in field environments, a required length of the pipe length 102 for agiven application can vary, and therefore the pipe lengths 102 cannot beprovided off-the-shelf in the required length for each application.Consequently, the ends of the pipe lengths 102 must be prepared in thefield for such methods, such as by welding on a flange, machining agroove, or cutting threads. Such methods can be time consuming andrequire expensive equipment and skilled labor to perform in the field.By contrast, with the mechanical joint 120 and the joint restraintassemblies 134 shown, the pipe length 102 can simply be cut to therequired length, and the mechanical joint 120 can be quickly completedwith only a wrench or other simple hand tools.

The joint restraint assemblies 134 are not limited to use in mechanicaljoints 120, and the joint restraint assemblies 134 can be disposeddirectly on the piping element 110 rather than on the gland 124. Forexample, the piping element 110 can be a coupling which forms a sealwith the pipe lengths 102 by a means other than compressing the gasket228 with the gland 124. In such application, the joint restraintassemblies 134 can be attached directly to the pipe coupling. In otheraspects, the joint restraint assembly 134 can be attached to pipingelements 110 such as valves, hydrants, couplings, fittings, or othersuitable types of piping elements.

The gland 124 and the grippers 232 can comprise a material such as castiron, ductile iron, steel, brass, metal, plastic, or any other suitablematerial. In some aspects, the grippers 232 can be heat treated tostrengthen the gripping protuberances 430. In the present aspect, eitheror both of the gland 124 and the grippers 232 can be manufactured by acasting operation such as investment casting, die casting, sand casting,or any other suitable method of casting. In some aspects, a mold used tocast either or both of the gland 124 and the grippers 232 can be madethrough an additive manufacturing process such as 3D sand printing. Inother aspects, either or both of the gland 124 and the grippers 232 canbe formed by an additive manufacturing process such as 3D printing. Insome aspects, either or both of the gland 124 and the grippers 232 canbe formed by a metalworking process such as forging, sintering, metalinjection molding, machining, or any other suitable process. The pipelengths 102 can comprise a material such as polyvinyl chloride,chlorinated polyvinyl chloride, fiber-reinforced plastic, polypropylene,polyethylene, polybutylene, steel, iron, brass, copper, stainless steel,or any other suitable material.

One should note that conditional language, such as, among others, “can,”“could,” “might,” or “may,” unless specifically stated otherwise, orotherwise understood within the context as used, is generally intendedto convey that certain embodiments include, while other embodiments donot include, certain features, elements and/or steps. Thus, suchconditional language is not generally intended to imply that features,elements and/or steps are in any way required for one or more particularembodiments or that one or more particular embodiments necessarilyinclude logic for deciding, with or without user input or prompting,whether these features, elements and/or steps are included or are to beperformed in any particular embodiment.

It should be emphasized that the above-described embodiments are merelypossible examples of implementations, merely set forth for a clearunderstanding of the principles of the present disclosure. Any processdescriptions or blocks in flow diagrams should be understood asrepresenting modules, segments, or portions of code which include one ormore executable instructions for implementing specific logical functionsor steps in the process, and alternate implementations are included inwhich functions may not be included or executed at all, may be executedout of order from that shown or discussed, including substantiallyconcurrently or in reverse order, depending on the functionalityinvolved, as would be understood by those reasonably skilled in the artof the present disclosure. Many variations and modifications may be madeto the above-described embodiment(s) without departing substantiallyfrom the spirit and principles of the present disclosure. Further, thescope of the present disclosure is intended to cover any and allcombinations and sub-combinations of all elements, features, and aspectsdiscussed above. All such modifications and variations are intended tobe included herein within the scope of the present disclosure, and allpossible claims to individual aspects or combinations of elements orsteps are intended to be supported by the present disclosure.

That which is claimed is:
 1. A mechanical joint comprising: a pipingelement, the piping element comprising an element flange, the pipingelement defining a socket extending inwards from the element flange; apipe length, the pipe length extending through the element flange intothe socket, the pipe length defining an outer pipe surface; and a gland,the pipe length extending through the gland, the gland comprising ajoint restraint assembly, the joint restraint assembly comprising: arestraint base; and a gripper disposed within the restraint pocket, thegripper configured to rotate in the restraint pocket, the gripperfurther configured to engage the outer pipe surface to prevent removalof the pipe length from the socket.
 2. The mechanical joint of claim 1,wherein: the gripper defines an engagement end and a lever end disposedopposite from the engagement end; the gripper comprises a plurality ofgripping protuberances disposed on the engagement end; and at least aone of the gripping protuberances engages the outer pipe surface.
 3. Themechanical joint of claim 2, wherein: the engagement end of the gripperis configured to exert increasing pressure on the outer pipe surfacewhen the gripper is rotated in the restraint pocket in an engagementdirection; the gripper is configured to rotate in the restraint pocketin the engagement direction when the pipe length is moved in awithdrawal direction outwards from the socket; the engagement end isconfigured to exert decreasing pressure on the outer pipe surface whenthe gripper is rotated in the restraint pocket in a disengagementdirection; and the gripper is configured to rotate about the restraintpivot in the disengagement direction when the pipe length is moved in aninsertion direction into the socket.
 4. The mechanical joint of claim 3,wherein: the restraint base defines a stop surface; and the stop surfaceis configured to contact the lever end of the gripper to prevent furtherrotation of the gripper in the engagement direction and further movementof the pipe length in the withdrawal direction.
 5. The mechanical jointof claim 3, wherein: the joint restraint assembly further comprises aspring clip; and the spring clip biases the gripper to rotate in therestraint pocket in the engagement direction.
 6. The mechanical joint ofclaim 1, further comprising a gasket, and wherein: the pipe lengthextends through the gasket; the gasket is compressed between the pipingelement and the gland; and the gasket forms a seal with the outer pipesurface.